This application claims benefit of priority to Japanese Patent Applications No. JP10-249873 filed Sep. 3, 1998 and No. JP10-287843 filed Oct. 9, 1998, the entire contents of which are incorporated by reference herein.
1. Field of the Invention
The present invention relates to an elevator with improved railings provided on an upper side of a passenger cage along the top edges thereof.
2. Discussion of the Background
In general, elevators have been installed in a high rise building so that residents or the like can easily get to the desired upper or lower floors.
The conventional elevator, as shown in FIG. 1, is operated in an elevator shaft 1 extending vertically in the building, and includes a pair of guide rails 2 installed in the shaft 1, a cage 4 movably supported between the guide rails 2 via a cage frame 3, and a drive system 5 moving the cage 4 up and down. The drive system 5 is composed of cables (only one is shown) 6, two car sheaves 7, a counter weight sheave 8, a counter weight 9, and a hoisting machine 10 disposed in the upper part of the shaft 1 for driving the cables 6.
In this type of elevator where the hoisting machine 10 is disposed in the upper part of the shaft 1, thereby dispensing with a machine room located right above the shaft 1 in which a hoisting machine, a control panel and the like is conventionally installed, it is especially required to reduce the overhead measurements at the installation of the elevator so that the building space other than the shaft 1 can be used effectively. (The overhead measurements refer to a distance between a floor of the cage 4 and a ceiling of the shaft 1 at the time the cage 4 stops at the upper most floor.)
Practically speaking, the overhead measurements are determined by a distance between the highest object on the cage 4, that is guide shoes 11, and the lowest object on the ceiling part of the shaft 1, that is the ceiling of the shaft 1. Further, the distance from the highest object on the cage 4 to the lowest object on the ceiling of the shaft 1 can be affected by conditions of other components in the shaft 1 such as a stroke of a counter weight oil buffer (not shown), or a distance between the counter weight oil buffer and the counter weight 8.
Thus, to realize an elevator with small overhead measurements, it is necessary to reduce a distance between the highest object on the cage 4 and the ceiling of the shaft 1.
Furthermore, elevators are required to be inspected periodically, and on such occasions, maintenance workers sometimes inspect the elevators riding on the upper side of the cage 4. To ensure the safety of the maintenance workers, in general, railings 12 are provided on the upper side of the cage 4 along the side edges and back edge thereof. To realize an elevator with small overhead measurements, the height Y of railings 12 has to be lower than the height X of the highest object on the cage 4, i.e. the guide shoe 11.
However, if the height Y is lower than the height X, the railings 12 do not achieve the main object of ensuring the safety of the maintenance workers on the cage 4. On the other hand, if the height Y of the railings 12 becomes higher, the overhead measurements become longer, and as a result, it becomes impossible to realize an elevator with small overhead measurements.
Accordingly, one object of the present invention is to provide a novel elevator with small overhead measurements and which can ensure the safety of maintenance workers on the cage during an inspection by means of railings.
This and other objects are achieved according to the present invention by providing a new and improved elevator including a cage configured to ascend and descend in an elevator shaft, and a railing member disposed on the cage along a top edge thereof and configured to be adjustable in height.